German police investigate suspected pipe bomb at Bonn train station

German police are searching for a suspect after an abandoned bag loaded with potential explosives was discovered Monday at the central train station in Bonn, Spiegel Online reported Wednesday.

The German daily Frankfurter Allegemeine Zeitung, citing unnamed high level sources, reported that authorities determined the bomb was extremely dangerous, comparable to the 2004 attack in Madrid, in which 10 bombs placed on regional trains claimed 191 lives.

The station was temporarily closed.

Two Somali-born men, detained Tuesday in connection with the find, were later released for lack of evidence, Cologne police said, according to Spiegel.

The first suspect, identified as Omar D., was arrested on Tuesday around 1:30 p.m. in a Bonn Internet café along with his companion Abdifatah W., Spiegel Online reported Tuesday.

According to Spiegel, Omar D. was detained in 2008 at the Cologne/Bonn airport after boarding a plane to Amsterdam, along with another Somali native, both suspected of planning to join the armed jihad. Both were released shortly after their arrest at that time.

Spiegel Online reported that the bag at the train station contained butane gas and ammonium nitrate, as well as a metal pipe, an alarm clock and batteries. Investigators initially described the bag's contents as "potentially explosive material."

Police are working from a description of the man a 14-year-old boy said he saw deposit the bag at Track 1 of the train station, Spiegel Online reported.

Parts of the station were closed as authorities fired a water cannon at the bag to disable it.